Reducing packet loss at a wireless communication device due to a connection interruption

• US 9,451,497 B2
• Filed: 08/13/2013
• Issued: 09/20/2016
• Est. Priority Date: 08/13/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Vangala, Sarma V., Vallath, Sreevalsan, Balakrishnan, Swaminathan, Yerrabommanahalli, Vikram Bhaskara
• Primary Examiner(s): Hailu, Kibrom T
• Application Number:
  US13/966,203
• Publication Number:
  US 20140044046A1
• Time in Patent Office: 1,134 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 47/27 Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets
• CPC Class Codes: H04W 28/0273 adapting protocols for flow control or congestion control to wireless environment, e.g. adapting transmission control protocol [TCP] wireless network protocols or protocol adaptations to wireless operation, e.g. wireless application protocol H04W80/00

Abstract

A method for reducing packet loss during data transfer from a network to a wireless communication device over a connection is disclosed. The method can include the wireless communication device signaling a first receive window size for a data transfer; determining occurrence of an event resulting in an interruption of the connection; and, in response to determining occurrence of the event, signaling a second receive window size for the data transfer prior to the event to trigger an adjustment of a data rate of the data transfer in preparation for the event.

Claims

1. A method for reducing packet loss during a data transfer to a wireless communication client device over a connection, the method comprising the wireless communication client device:

signaling a first receive window size for the data transfer;

determining, before a connection interruption event, a time of the connection interruption event that results in an interruption of the connection, the connection interruption event including the wireless communication client device at least temporarily tuning from a first base station to a second base station; and

in response to determining the time of the connection interruption event, signaling a second receive window size for the data transfer prior to the connection interruption event to trigger an adjustment of a data rate of the data transfer in preparation for the connection interruption event,

wherein the second receive window size is based at least in part on a type of the connection interruption event,

wherein types of connection interruption events comprise at least a tune-away event type, a registration event type, a circuit switched fallback (CSFB) event type, and an inter radio access technology (iRAT) transition event type,

wherein signaling the second receive window size comprises signaling the second receive window size based at least in part on an indication provided by a physical layer to a higher layer in advance of the connection interruption event,

wherein the indication communicates knowledge of a forthcoming interruption in a physical layer connection to a first network, and

wherein the indication includes the type of connection interruption event, an event time at which the connection interruption event occurs, and a time duration of the connection interruption event.

2. The method of claim 1, wherein when the type of connection interruption event is the tune-away event type, signaling the second receive window size for the connection interruption event comprises signaling a zero window receive window size to stall the data transfer during the connection interruption event, the method further comprising the wireless communication client device:

signaling a third receive window size configured to trigger resumption of the data transfer following the connection interruption event.

3. The method of claim 2, wherein signaling the third receive window size configured to trigger resumption of the data transfer comprises resending signaling of the first receive window size.

4. The method of claim 2, wherein the tune-away event type comprises a tune-away period in which a radio of the wireless communication client device is temporarily tuned from the first base station to the second base station.

5. The method of claim 1, wherein the first base station implements a first radio access technology (RAT) and the second base station implements a second RAT, the second RAT supporting a different data rate than the first RAT, and wherein, when the type of connection interruption event is the iRAT transition event type:

determining the time of the connection interruption event comprises determining when an iRAT transition from the first RAT to the second RAT occurs; and

signaling the second receive window size comprises preemptively signaling a receive window size selected based at least in part on a data rate supported by the second RAT prior to the iRAT transition to trigger adjustment of the data rate of the data transfer in preparation for the iRAT transition.

6. The method of claim 1, wherein the type of connection interruption event is the registration event type performed attendant to a transition of the wireless communication client device from the first base station to the second base station, and wherein signaling the second receive window size for the registration event type comprises signaling a zero window receive window size.

7. The method of claim 1, wherein the first base station implements a Long Term Evolution (LTE) radio access technology (RAT) and the second base station implements a legacy RAT having a circuit switched domain, and wherein the type of connection interruption event is the CSFB event type performed in response to a voice call, and wherein signaling the second receive window size for the CSFB event type comprises signaling a zero window receive window size.

8. The method of claim 1, wherein signaling the second receive window size comprises signaling the second receive window size at a time prior to the connection interruption event determined based at least in part on an observed round trip time (RTT) for the data transfer to enable a sender to receive the second receive window size and adjust a data rate of the data transfer sufficiently in advance of the connection interruption event to prevent packet loss during the connection interruption event.

9. The method of claim 1, wherein the indication is provided by the physical layer to the higher layer via an intermediate layer in the wireless communication client device when the physical layer does not directly communicate with the higher layer.

10. The method of claim 1, wherein the connection interruption event comprises a scheduled tune-away period that comprises a known time duration.

11. A wireless communication client device comprising:

a radio configured to support communication with a first network and a second network; and

processing circuitry coupled with the radio, the processing circuitry configured to control the wireless communication client device to at least;

signal a first receive window size for a data transfer to the wireless communication client device via a connection;

determine a time, in advance of a connection interruption event, at which to signal an event-appropriate receive window size to enable a data source on the connection to receive an updated receive window size and adjust a data rate of the data transfer;

signal the updated receive window size for the data transfer in advance of the connection interruption event; and

signal another receive window size configured to trigger resumption of the data transfer over the first network after the connection interruption event,

wherein the event-appropriate receive window size is based at least in part on a type of the connection interruption event,

wherein signaling the updated receive window size comprises signaling the updated receive window size based at least in part on an indication provided by a physical layer to a higher layer in advance of the connection interruption event,

wherein the indication communicates knowledge of a forthcoming interruption in a physical layer connection to a first network, and

wherein the indication includes the type of connection interruption event, an event time at which the connection interruption event occurs, and a time duration of the connection interruption event.

12. The wireless communication client device of claim 11, wherein the processing circuitry is further configured to control the wireless communication client device to:

calculate a round trip time (RTT); and

use the calculated RTT to determine the time at which to signal the event-appropriate receive window size before the connection interruption event occurs.

13. The wireless communication client device of claim 11, wherein, when the type of the connection interruption event comprises a tune-away event type, the updated receive window size comprises a zero window receive window size, and wherein the tune-away event type comprises the radio tuning away from the first network to the second network for a tune-away period and the radio tuning back to the first network following the tune-away period.

14. The wireless communication client device of claim 11, wherein, when the type of the connection interruption event comprises a registration event type, the updated receive window size comprises a zero window receive window size.

15. The wireless communication client device of claim 11, wherein, when the type of the connection interruption event comprises a circuit switched fallback (CSFB) event type, the updated receive window size comprises a zero window receive window size.

16. The wireless communication client device of claim 11, wherein, when the type of the connection interruption event comprises an inter radio access technology (iRAT) transition event type between the first network that implements a first radio access technology (RAT) and the second network that implements a second RAT, the updated receive window size is based at least in part on the data rate supported by the second RAT as compared with the data rate supported by the first RAT.

17. A non-transitory computer-readable storage medium, storing a set of computer program instructions for reducing packet loss during a data transfer to a wireless communication client device over a connection via a first network, that when executed by one or more processors of a wireless communication client device, cause the wireless communication client device to:

signal a first receive window size for the data transfer to the wireless communication client device over the connection;

determine, before a connection interruption event, a time at which to signal an event-appropriate receive window size to enable a data source on the connection to receive a second receive window size and to adjust a data rate of the data transfer; and

signal, at the determined time, the second receive window size before the connection interruption event,

wherein the event-appropriate receive window size is based at least in part on a type of the connection interruption event,

wherein types of connection interruption events comprise at least a tune-away event type, a registration event type, a circuit switched fallback (CSFB) event type, and an inter radio access technology (iRAT) transition event type,

wherein signaling the second receive window size comprises signaling the second receive window size based at least in part on an indication provided by a physical layer to a higher layer in advance of the connection interruption event,

wherein the indication communicates knowledge of a forthcoming interruption in a physical layer connection to a first network, and

wherein the indication includes the type of connection interruption event, an event time at which the connection interruption event occurs, and a time duration of the connection interruption event.

18. The non-transitory computer-readable storage medium of claim 17, wherein when the type of the connection interruption event comprises a tune-away event type, a registration event type, or a circuit switched fallback (CSFB) event type, the second receive window size comprises a zero window receive window size.

19. The non-transitory computer-readable storage medium of claim 17, wherein, when the type of connection interruption event comprises an inter radio access technology (iRAT) transition event type between the first network that implements a first radio access technology (RAT) and a second network that implements a second RAT, the second receive window size is based at least in part on the data rate supported by the second RAT as compared with the data rate supported by the first RAT.

20. The non-transitory computer-readable storage medium of claim 19, wherein,

when the second RAT supports a higher data rate as compared with the first RAT, the second receive window size is larger than the first receive window size, and

when the second RAT supports a lower data rate as compared with the first RAT, the second receive window size is smaller than the first receive window size.